DD7 has two close friends, B(oy) and G(irl). The three have been pretty much inseparable since reception. I just found out that B has been asking the girls to show them their privates. He doesn't show his. He makes them promise not to tell. DD mentioned it almost by accident when upset about something unrelated, and when I enquired about what she exactly meant, she told me - very matter of factly. She said it made her not very comfortable, but 'he makes them do it, she had promised, and he is their friend'. It apparently happened more than once.
I called G's mother. However, when confronted, G. denied everything to her parents. After mother told me this, we decided to wait and see, as the girls' stories don't match.
Then yesterday, DD told me again - without prompting I may add, and without her displaying any form of judgment; she doesn't seem to realise any of the implications. She casually added he is actually looking inside. I fully believe her. I am in no way cross with DD or letting on how I feel. I am of course reinforcing the good vs bad secrets and good vs bad promises, and the underpants rule and everything else I can think of.
Now what to do? Do I tell B's parents (mother is known to believe he can do no wrong)? The school? I don't want DD to be caught up in a full 'he said - she said' situation. Mother of G is not (yet?) backing me up in light of G's denials; I did inform her of DDs last addition to the story - should I see if she can talk to G again (but I don't want to cause any issues for G) and give it a few days? I have to add B is quite manipulative, and has a history where he was already caught hitting both girls in Y1, which was dealt with by their teacher at the time. WWYD?